Marathon is the ultimate memory demon. It's not the hardest memory level (even though it's much harder than it looks and thoroughly deserves its extreme demon rating) but no other level in the game leans into the pure memory gimmick as much as this. Most impressive though, is how a level with such simple decoration, limited to only cube gameplay for over 4 minutes, manages to remain so engaging for its entire duration.

The decoration in Marathon is reminscient of the decoration found in early Geometry Dash levels, but it doesn't categorise itself under any specific update other than being primarily pre-2.0. Sections are typically comprised of suitably basic block deco and one main colour, although there's some subtle pulsework in many parts which is certainly more similar to modern levels. None of this is to say the level is ugly though; it's actually consistently pleasant to look at, and the sheer number of ideas constantly being used makes every part feel unique. Later sections also typically are more interesting to look at, not only through pulses, but also through art and sculptures. It's easy to find this level a little too plain (especially in the earlier, longer, slower sections) but there's undeniable charm to be found here.

The gameplay is the more interesting feature of this level. This is a long level and to have constantly evolving memory gameplay using only pre-2.0 cube gameplay is a serious feat. Marathon is backed by a frantic, ever-accelerating song which means that the gameplay is constantly speeding up, which allows for later sections to feel a lot more lively than the first few. While the first four sections are a standard (yet high quality) memory section, and the fifth is the same but mini, most sections from here all use a slightly different gimmick. There's chaotic messes of floating platforms, repetitive mazes where rhythm is the only guide, a completely airborn section using only orbs which houses a brilliant trick, surprisingly well-synced duals, and the iconic blind section near the end. There's also a few sections where memory takes a backseat in favour of pure timings - these are very welcome and don't take anything away from the level as a whole. Perhaps the only real flaw is a reliance on a few particularly difficult timings to really crank the difficulty up. These chokepoints are annoying but probably unavoidable in a level like this. The timing aspect of Marathon is actually the main source of difficulty, because this is not a level that completes itself once learnt. From 0, this is a slog of a level and can be as much a mental challenge as a physical one.

It's difficult to compare Marathon to most other levels because it's so different to what we're used to, which is interesting because it seems like it should feel like quintessential Geometry Dash. That's no problem though - much like a real marathon, the experience of completing it speaks for itself.